These roofing systems are typically a single sheet, reinforced in the middle with either a polyester or fiberglass mat for strength and modified with rubberized asphalt.  This allows the roof to expand and contract with building movement.  The Modified sheet should be installed over a mechanically fastened base-sheet.  These systems are mopped in place with hot asphalt.  These roof systems are also installed using a cold process called permanent bond.  It is applied with a torch to melt it to the base sheet.  The surfaces of the modified bitumen roof  are either smooth or granular finish that come in a selection of colors.

Uses:

These roof systems are used as an upgrade from built-up roofing systems. 

Life Span:

The expected life span of this system will exceed 15 years.  The roofing industry has seen excellent results from the modified bitumens roof.

Caution:

• Torch applied systems can be dangerous and can cause fires.  Extra attention in the application phase is very important.

Limitations:

Proper installation of this roof system is critical.  Details in the construction and installation procedures need to be planned very carefully.